Sickle bar grinder



Sept. 13, 1955 MOULTON SICKLE BAR GRINDER 2 Sheets-Sheet 1 Filed June12, 1953 INVENTOR A uvpew L. M001. roxv BY yrsm ,20 HFL ATTORNEYS p 13,1955 L. MOULTON 2,717,477

SICKLE BAR GRINDER Filed June 12, 1955 2 Sheets-Sheet 2 66' INVENTORA/IVDi/V A, Mil/L 77A United States Patent This invention relates tosickle bar grinders and more particularly to a grinder for grinding thecutting edges of the blade sections of sickle bars for mowing machinesand similar implements.

It is among the objects of the invention to provide an improved sicklebar grinder having a rigid frame on which a sickle bar to be ground isrigidly supported and a grinding wheel carriage movable along the frameto the different blade sections of the associated sickle bar, so thatthe grinder has a total length not materially in excess of the length ofthe longest sickle bar to be ground thereon and thus, requires a minimumof operating space; which provides freedom of manually controlledmovement of the grinding wheel toward and away from the blade sectionedges along the blade section edges, so that these edges can beaccurately ground to a sharp and straight condition; which providesadjustment of the sickle bar holding means to compensate for wear of thegrinding wheel; which can be provided in a movable form having anintegrally incorporated supporting stand or in a stationary form andmounted on a fixed support, such as a building wall; and which is simpleand durable in construction, economical to efi'icient in use. v

Other objects and advantages will become apparent from a considerationof the following description and the appended claims in conjunction withthe accompanying drawings wherein:

Figure 1 is a front elevational view of a sickle bar grinderillustrative of the invention;

Figure 2 is a transverse cross sectional view on an enlarged scale onthe line 22 of Figure 1;

Figure 3 is a fragmentary front. elevational view of the grinder on anenlarged scale showing structural details of the grinder;

Figure 4 is a top plan view of the fragmentary portion of the. grinderillustrated in Figure 3;

Figure 5 is a transverse cross sectional view on the line 55 of Figure3;

Figure 6 is a fragmentary perspective view of the grinder frame showingstructural details thereof; and

Figure 7 is an end elevational view of the frame showing a modified formof grinder frame.

With continued reference to the drawings, the grinder comprises a frame,generally indicated at 10, including a pair of posts 11 and 12 disposedin upright and spaced apart and substantially parallel relationship toeach other, a guideway structure or track 13 extending along the bottomends of the posts and rigidly secured thereto, a rail 14 extending pastthe upper ends of the posts and disposed above and parallel to theguideway structure 13,

manufacture, and effective and and arms 15 and 16 connected each at oneend to the rail 14 at spaced apart locations along the rail andprojecting perpendicularly in the same direction from the rail. The arm15 is pivotally connected at its end remote from the rail 14 to theupper end of the post 11 by a pivot bolt 17 which can be tightened tolock the arm in selected positions of angular adjustment relative to theassociated post and the arm 16 is secured to the post 12 by a similarbolt 18.

Screw clamps 20 to 23 inclusive, are mounted on the rail 14, one at eachend of the rail, and the other two at locations spaced apart along thelength of the rail and project from the rail in a direction away fromthe side of the rail remote from the posts 11 and 12, and these screwclamps rigidly secure a sickle bar 24 to the rail with the bladesections 25 of the sickle bar from the side of the rail remote from theposts 11 and 12 and substantially horizontally disposed, as illustratedin Figure 5.

The guide structure 13 is an elongated bar or rail of right angularcross sectional shape and is mounted on the posts 11 and 12, so that thelegs 26 and 27 thereof are inclined symmetrically outwardly anddownwardly from the edge of the member at which the corresponding edgesof the legs are joined.

A carriage 30 of right angular cross sectional shape is disposed on theguide structure 13 and carries antifriction rollers 31 to 34 inclusive,one at each corner thereof, which rollers bear on the upper surfaces ofthe legs 26 and 27 of the guide structure 13 near the outer edges ofthese legs to support the carriage on the guide structure for freetranslational movement along the guide structure. Brackets 35 and 36 aremounted on the upper surfaces'of the angularly disposed sides of thecarriage 30 and project outwardly beyond the outer edges of thecorresponding carriage sides, and peripherally grooved rollers 37 and 38are journaled on the outer ends of these brackets and engaged the outeredges of the legs 26 and 27 of the guide structure 13 to hold thecarriage in place on the guide structure.

It will be noted that the posts 11 and 12 are provided at their lowerends with hook formations having upwardly directed terminal portions 40and 41 which extend upwardly to the under surface of the guidestructure13 and are rigidly secured to the guide structure by suitable means,such as welding, to rigidly secure the posts to the guide structure.

Apertured lugs 43 and 44 extend transversely of and upwardly from thecarriage 30 at locations spaced apart along the carriage and aredisposed substantially parallel to each other. An upright structureincluding a rotatable grinding wheel and power means operativelyconnected thereto is superimposed upon the carriage 30 and is connectedat its lower end to the carriage for rocking movement about a horizontalaxis toward and away from the sickle bar supporting means or rail 14.Specifically, an L-shaped bracket, generally indicated at 45, has a baseportion 46 of rectangular shape disposed between the lugs 43 and 44 andpivotally secured to these lugs by rivets 47 and 48 respectively, forrocking movements of the bracket relative to the carriage about an axisdisposed parallel to the guide structure 13. A stop or abutment 49 ismounted on the side of the carriage 30 remote from the posts 11 and 12,and extends upwardly from the carriage to engage the bottom edge of thebracket base 46 to limit rocking movements of the bracket in a directionaway from the rail 14 for a purpose which will presently appear. p

A standard 50 is secured to the base 46 at the side of the base remotefrom the posts 11 and 12 and extends perpendicularly upwardly from thebase to a location slightly below the level of the rail 14. An arm 51 ispivotally secured atone end to the standard 50 at a location immediatelyabove the bracket base 46 by a rivet or bolt 52 extending transverselythrough the bracket and throughthe adjacent end of the arm and this armextends from the standard 50 toward a plane including the longitudinalcenter lines of the frame posts 11 and 12 of the grinder. An electricmotor 53 is mounted on the arm projecting 51 and is connected to a powersource by an extension cord of sufiicient length to permit movement ofthe motor with the bracket and carriage 30 longitudinally of the guidestructure 13 from one end to the other end of the guide structure.

A second arm 54 is pivotally connected at one end to the upper end ofthe standard by a pin or rivet 55 extending transversely through thestandard and the corresponding end of the arm and this arm also projectsfrom the standard toward a plane including the longitudinal center linesof the frame posts.

A bearing sleeve 56 extends transversely through and is secured in thearm 54 at the end of this arm remote from the standard 50, and a shaft57 extends through and is journaled in the bearing sleeve 56 forrotation about an axis parallel to the guide structure 13. A double beveled grinding wheel 58 is mounted on the shaft 57 at one end of thebearing sleeve 56 and a belt pulley 60 having a diameter less than theminimum diameter of the grinding wheel 58 is mounted on the other end ofthe shaft 57. A belt wheel 61 is mounted on the shaft 62 of the motor 53and a V-belt 63 drivingly connects the motor belt pulley 61 to thegrinding wheel belt pulley 60.

' An adjustable length link 65 is pivotally connected at one end to thearm 54- intermediate the length of this arm and is pivotally connectedat its other end to the arm 51 intermediate the length of the latter armfor varying the distance between the arms 51 and 54 and therebymaintaining the drive belt 63 under the proper tension. A handle 66 issecured at its lower end to the standard 50' near the upper end of thestandard, and projects upwardly above the upper end of the standard toprovide a handle for rocking the bracket 45 about the axis of the pivotpins or rivets 47 and 48 to move the grinding wheel 58 along the cuttingedges of the blade section 25 of a cutter bar clamped to the rail 14.

A hand lever 68 is secured at its lower end to the upper arm 54 andextends upwardly from the upper arm in spaced relationship to the handle66. This hand lever, when moved toward or away from the handle 66,raises or lowers the grinding wheel 58 relative to the cutter bar 24, sothat the proper pressure can be manually exerted between the grindingwheel and the blade sections of the sickle bar as the wheel is movedalong the cutting edges of the blade sections by rocking the bracket 45.

An angle bracket 70 is secured to the arm 54 at the under side andintermediate the length of this arm, and depends downwardly from thearm, and a compression spring 71 is disposed between the bracket 70 andthe adjacent side of weight of the grinding wheel, the bearing sleeve,the grinding wheel shaft and the motor, so that the grinding wheel canbe raised with moderate manual effort. The handle 66 and hand lever 68are so disposed relative to each other, that one hand of an operator canbe placed around both of these members and the lever 68 can be movedtoward the handle 66 to raise the grinding wheel by merely using thegrip of the operators hand in a compressive manner.

The grinding wheel and its supporting carriage can be moved along theguideway structure 13 to successively position the grinding wheel in thenotches between ad jacent blade sections of the associated sickle bar,and with the motor 53 in operation, the grinding wheel can be pressedagainst the beveled sides of the cutting edges of the blade sectionswith the proper pressure, and moved back and forth along the cuttingedges of the blade sections until the cutting edges of the sections areground to a straight and sharp condition, the arrangement providing ahigh degree of sensitivity and accuracy for the grinding operation.

' In the form of the invention. shown in Figure 1, legs 72 and 73 areintegrally joined at their upper ends to the bottom ends of the frameposts 11 and. 12 respectively, and extend downwardly from the frameposts in longithe standard 50 and counterbalances the tudinal alignmenttherewith. Base plates 74 and 75 are secured to the bottom ends of thelegs 72 and 73 respectively, substantially perpendicular to thelongitudinal center lines of these legs, and support the grinder on ahorizontal supporting surface, such as the ground or a building floor.This form of the invention is movable and in this form, the grinder maybe carried from place to place, as desired. In the arrangement shown inFigure 7, the legs 72 and 73 and the base plates 74 and 75 are omitted,and the posts are provided at locations spaced apart therealong withapertured angle brackets, as indicated at 76 and 77 in Figure 7, andscrew fasteners, as indicated at 78 and 79, may be inserted through theapertures in the angle brackets and threaded into a vertical supportingstructure, such as a building wall 80, to support the grinder in astationary position.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are, therefore, to be considered in all respects asillustrative. and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are, therefore, intended to be embracedtherein.

What is claimed is:

1. A sickle bar grinder comprising a frame including upright postsdisposed in spaced apart relationship to each other, a guidewaystructure extending along the lower ends of said posts and rigidlysecured thereto, a rail extending along the upper ends of said posts anddisposed above and parallel to said guideway structure, means mountingsaid rail on said post for movements of, adjustment of said rail towardand away from said guideway structure, clamps carried by said rail atlocations spaced apart therealong for clamping a sickle bar tosaid rail,a carriage mounted on said guideway structure, rollers supporting saidcarriage on said guideway structure for movement of the carriagelongitudinally of the guideway structure, a bracket pivotally mounted onsaid carriage for rocking movements about an axis sub stantiallyparallel to said guideway structure and including a base and a standardupstanding from said base, arms pivotally mounted on said standard atlocations spaced apart along the latter and extending from said standardtoward a plane including the longitudinal center lines of said posts, adouble beveled grinding wheel journaled on the uppermost of said armsfor rotation about an axis substantially parallel to said guidewaystructure, a motor mounted on the lowermost of said arms and drivinglyconnected to said grinding wheel, adjustable length meansinterconnecting said arms, a handle extending above the upper end ofsaid standard for rocking said bracket on said carriage to move saidgrinding wheel along the edges of the blade sections of a sickle barclamped to said. rail, and a lever secured to said uppermost arm andextending. therefrom in spaced relationship to said handle for movingsaid grinding wheel toward and away from the associated sickle bar bladesections. v

2. A sickle bar grinder comprising spaced posts, means carried by theupper ends of said posts for supporting a sickle bar to be sharpened, atrack arranged on one side of and spaced from said posts and extendingfrom one to the other of said posts, a carriage connected to said trackfor. back and forth movement therealong, an upright structure includingan upstanding L-shaped bracket having its short leg connected adjacentits free end to said carriage for rocking movement about a horizontalaxis toward and away from said sickle bar supporting means, a motorarranged in superimposed spaced relation with respect to the short leg;of said bracket and carried by the long. leg of said bracket, arotatable. grinding wheel arranged in parallel superimposed relationwith respect to said motor i and carried by the long leg of said bracketand drivingly' connected to said motor, and hand actuable means on thelong leg of said bracket adjacent its free end for efiecting the rockingmovement of said bracket.

3. A sickle bar grinder comprising spaced posts, means carried by theupper ends of said posts for supporting a sickle bar to be sharpened, atrack arranged on one side of and spaced from said posts and extendingfrom one to the other of said posts, a carriage connected to said trackfor back and forth movement therealong, an upright structure includingan upstanding L-shaped bracket having its short leg connected adjacentits free end to said carriage for rocking movements about a horizontalaxis toward and away from said sickle bar supporting means, a motorarranged in superimposed spaced relation with respect to the short legof said bracket and carried by the long leg of said bracket, a rotatablegrinding wheel arranged in parallel superimposed relation with respectto said motor and carried by the long leg of said bracket and drivinglyconnected to said motor, hand actuable means on the long leg of saidbracket adjacent its free end for efiecting the rocking movement of saidbracket, and spring means operatively connected to the long leg of saidbracket and said grinding wheel for biasing said structure toward saidsickle bar supporting means.

4. A sickle bar grinder comprising spaced posts, means carried by theupper ends of said posts for supporting a sickle bar to be sharpened, atrack arranged on one side of and spaced from said posts and extendingfrom one to the other of said posts, a carriage connected to said trackfor back and forth movement therealong, structure including anupstanding L-shaped bracket having its short leg connected adjacent itsfree end to said carriage for rocking movement about a horizontal axistoward and away from said sickle bar supporting means, a motor arrangedin superimposed spaced relation with respect to the short leg of saidbracket and carried by the long leg of said bracket, a rotatablegrinding wheel arranged in parallel superimposed spaced relation withrespect to said motor and carried by the long leg of said bracket anddrivingly connected to said motor, hand actuable means on the long legof said bracket adjacent its free end foreflfecting the rocking movementof said bracket, and an upstanding abutment on said carriage andengageable with the short leg of said bracket for limiting the rockingmovement of said bracket away from said sickle bar supporting means.

References Cited in the file of this patent UNITED STATES PATENTS2,456,827 Greeley Dec. 21, 1948 2,482,934 Rainbolt et a1 Sept. 27, 19492,486,119 Coifeen Oct. 25, 1949 2,520,210 Howell Aug. 29, 1950 2,582,607Rinne Jan. 15, 1952 2,654,187 Ferrin Oct. 6, 1953 2,659,184 Mead et a1.Nov. 17. 1953 an upright

